ARM: mach-loki: delete

This was introduced more than 3 years ago, and since then only generic
janitorial changes were made without further addition of actual support
for "real" devices.  This is therefore a cost with no benefits to keep
in the tree.  If someone wishes to revive this code, it is always
possible to retrieve it from the Git repository.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
CC: Ke Wei <kewei@marvell.com>
CC: Saeed Bishara <saeed@marvell.com>
CC: Lennert Buytenhek <buytenh@wantstofly.org>